Aviation fuel and emissions in air markets with interregional passenger leakage
Transportation Research Part D: Transport and Environment, 2021
Attractive air services at large airports in the U.S., over the last two decades, have encouraged... more Attractive air services at large airports in the U.S., over the last two decades, have encouraged interregional air passenger leakage, a phenomenon in which air travelers abandon their nearby small airports in favor of starting their air journeys from large hub airports farther away. The disparities between small and large airports, in terms of air services, are expected to widen because of COVID-19 and further exacerbate passenger leakage. This study estimates the differences in mean aviation fuel consumed and pollutants emitted between air routes from small and large airports in the U.S. Midwest region – routes that are known to be contested according to analysis of an air ticket dataset. Findings indicate that air journeys originating from large airports result in 24% less aviation fuel consumption and considerably lower emissions at the passenger-kilometer level, offering additional insight toward better understanding the environmental impact of a geographically shifting air travel demand.
Transportation Infrastructure Decision Flexibility in Response to Climate Change and Demand Uncertainties: The Mackenzie Valley Highway in Canada’s Northwest Territories
Transportation Research Part A: Policy and Practice, 2020
Historically an important transportation corridor in the Northwest Territories, climate change ha... more Historically an important transportation corridor in the Northwest Territories, climate change has shortened the duration of the Mackenzie River's navigational season. Communities rely increasingly on airlift as the growing volatility affects barging operations, leading to higher overall freight costs. Using an options approach, we present a methodological framework that supports flexible infrastructure decision making, accounting for the impacts of climate change uncertainty. We apply this method to the decision of whether to continue barging on the Mackenzie River, or connect the entire corridor by extending the all-weather Mackenzie Valley Highway, explicitly considering uncertainties in river barging conditions. We first model river open season days as a stochastic process; barging is dependent on the number of open season days, which in turn is affected by climate change. Second, we evaluate the expected cost of barging and airlift each season using a modified Black-Scholes model. Finally, we use real options to determine how long construction of the all-weather highway may be deferred. The results indicate that it is advisable to defer construction nearly a decade, in balancing the costs of construction against climate change uncertainty. This paper demonstrates that when we explicitly incorporate the impact of climate change on project valuations, particularly those in northern and Arctic Canada where these impacts are considerable, project valuations can change significantly such that all-weather road construction is supported, even if it is deferred to future years. This method can assist federal and territorial governments in communicating the impacts of climate change on communities, and provide another tool to support multi-layered, complex transportation infrastructure investment decisions that address these rapidly changing environments.
This paper presents a method for obtaining airfield capacity estimates, using historical data fro... more This paper presents a method for obtaining airfield capacity estimates, using historical data from the Federal Aviation Administration's Aviation Systems Performance Metrics (ASPM) database. The process first involves merging individual flights and quarter-hour airport runway operations datasets from ASPM to create a new dataset. Data for Newark International Airport and San Diego International Airport from 2006 to 2011 was used. Secondly, filters for meteorological condition, runway configuration, called rates, and fleet mix were applied to the two airport datasets. The filtered datasets were then used in a censored regression model of capacity that includes queue length (number of aircraft waiting to arrive/depart) and arrival/departure throughput count splits as independent variables. These attributes were found to impact airfield capacity at statistically significant levels, and parameters had expected signs and magnitudes. Additionally, capacities under ideal conditions were found to be reasonably close to other sources. The model also confirmed that average capacities at EWR during hours when a Ground Delay Program (GDP) was running were lower than when there was no GDP in effect. The method described in this paper can be used to more precisely quantify airfield capacities in specific conditions of particular interest to air traffic controllers and airport operators, to better facilitate decisions that rely heavily on a good understanding of capacity in these conditions. The data exploration and preparation undertaken as part of the study reveals some of the finer points of the ASPM data and how it can be used in a more meaningful way for airfield capacity estimation.
This paper introduces an empirically driven, nonparametric method to isolate and estimate the eff... more This paper introduces an empirically driven, nonparametric method to isolate and estimate the effects of demand and throughput changes to observed changes in flight delay. Classical queuing model concepts were used to develop a method by which an intermediate queuing scenario could be constructed, in order to isolate the delay effects due to shifts in demand and throughput. This method includes the development of a stochastic throughput function that is based entirely on data and as a result has two advantages: it uses non-parametric, empirically-based probability distributions, and capacity need not be estimated explicitly. The method was applied to a case study of the three major New York airports of LaGuardia (LGA), John F. Kennedy (JFK), and Newark Liberty (EWR), for the peak summer travel seasons of 2006 and 2007, using data extracted from ASPM. This case study was of particular interest given that these airports experienced record levels of delay in 2007. The simulation results were consistent with both OPSNET and ASPM data, and were successful in quantifying the delay effects of demand and throughput changes from 2006 to 2007.
Count Models to Represent the Impacts of Weather and Infrastructure on Flight Disruptions
Transportation Research Record: Journal of the Transportation Research Board
This paper explores the application of count models to represent the relationship between flight ... more This paper explores the application of count models to represent the relationship between flight disruptions and weather. Throughout the world, flights are regularly disrupted by delays at airports and in the terminal airspace, and less frequently by diversions and cancelations. Many delay studies have been conducted for large American and European airports, in part due to the availability of high-quality data. However, such high-quality data is not as readily available for other airports throughout the world. In this study, excess-zero count models are built using a publicly available dataset for Iqaluit Airport (YFB) in Northern Canada, to determine the influence of different weather components on disruption counts. Visibility and crosswind speeds are shown to have the largest influence on flight disruptions. The models are also applied using Aviation System Performance Metrics (ASPM) flight data for Anchorage Airport (ANC) in Alaska; the data is systematically degraded to match c...
Corrigendum to “Incorporating the impacts of climate change in transportation infrastructure decision models” [Transport. Res. Part A: Policy Pract. 134 (2020) 271–287]
Transportation Research Part A: Policy and Practice
This paper describes a study undertaken to assess the speed and safety effects of reducing speed ... more This paper describes a study undertaken to assess the speed and safety effects of reducing speed limits from 50 to 30 km/h in school zones. Mean speeds and 85th percentile speeds were reduced by 12.2 and 11.6 km/h, respectively. Speed variation was also reduced, and the speed cumulative distributions shifted to the left, indicating further reductions for all speed ranges. The safety evaluation results revealed fatal and injury collisions were significantly reduced by 45.3% and injuries to vulnerable road users were reduced by 55.3%. In fact, for every 1 km/h reduction in mean speed, fatal and injury crashes were reduced by about 4%, which is consistent with findings from previous research. Neither spatial nor temporal collision migration or spillover effects were significant factors in the analysis. Consequently, the results of this study provide strong evidence that reducing speed limits to 30 km/h in school zones can bring significant safety benefits by reducing vehicular speeds a...
Towards Establishing Effective Commercial Driver Training Standards: Analysis of Industry opinions from Alberta
Canadian Journal of Civil Engineering
Commercial driver licensing programs ensure that drivers have the appropriate skills to perform t... more Commercial driver licensing programs ensure that drivers have the appropriate skills to perform their duties in a safe and efficient manner. Establishing such standards with good compliance requires understanding industry professionals’ opinions on aspects of current training. In this paper achieving that objective is attempted through analyzing opinions of employees of Alberta Motor Transportation Association’s member companies. Participants included commercial drivers, managers, and training staff. Participants were questioned about the commercial driving and training experience, and attitudes towards standard training. Also, the survey questioned respondents on specific training courses when considering them from several different perspectives. Overall, the results show high acceptance and need for standard training. The results support establishment of a program that increases basic pre-licensing training, requires specific training classes to be taken by drivers, and specifies ...
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Papers by Amy M Kim